1. Field of the Invention
This invention relates to a semiconductive resin composition, particularly a semiconductive resin composition having a good easy peelability from an electrically insulating layer and extrudability, and a power transmission cable using that semiconductive resin composition in an outer semiconductive layer. It also relates to a semiconductive resin composition capable of forming an outer semiconductive layer excellent in electrical properties and mechanical properties, and to a power transmission cable using that semiconductive resin composition.
2. Description of the Related Art
Conventionally, power transmission cables are widely used, which are provided with an outer semiconductive layer around an electrically insulating layer made of a crosslinked polyethylene. (Refer to e.g. JP-A-1-246708.) The outer semiconductive layer is required to be in close contact with the electrically insulating layer, so as not to cause a corona discharge. On the other hand, when performing a terminal treatment for cable connection, etc., it is necessary to be able to easily remove the electrically insulating layer without damaging it. Therefore, the outer semiconductive layer having good adhesion and easy peelability from the electrically insulating layer is desired.
To produce such an outer semiconductive layer, there has conventionally been used the semiconductive resin composition derived from combining a base polymer made of a mixture of a polymer having no affinity for the electrical insulator, such as a polar polymer such as vinyl chloride, chlorinated polyethylene, ethylene vinyl acetate copolymer or the like, fluorine resin, silicone resin or the like, and a polyolefin resin, with an electrically conductive carbon black.